<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    /* 定义id选择器 */
    #blue{
      color: skyblue;
    }
  </style>
</head>
<body>

<div id="blue">这个文字是蓝色的</div>
<p id>111</p>
</body>
</html>
